Merge branch 'bitstreamout/procps-procio'

References:
 procps-ng/procps!56

Makefile.am

@@ -233,6 +233,8 @@ proc_libprocps_la_SOURCES = \
 	proc/escape.h \
 	proc/numa.c \
 	proc/numa.h \
+	proc/procio.c \
+	proc/procio.h \
 	proc/procps-private.h \
 	proc/procps.h \
 	proc/pwcache.c \
@@ -258,6 +260,7 @@ proc_libprocps_la_include_HEADERS = \
 	proc/devname.h \
 	proc/escape.h \
 	proc/numa.h \
+	proc/procio.h \
 	proc/procps.h \
 	proc/pwcache.h \
 	proc/readproc.h \
@@ -269,6 +272,7 @@ proc_libprocps_la_include_HEADERS = \
 	proc/whattime.h
 
 dist_man_MANS += \
+	proc/procio.3 \
 	proc/openproc.3 \
 	proc/readproc.3 \
 	proc/readproctab.3

proc/libprocps.sym

@@ -8,6 +8,7 @@ global:
 	escape_str;
 	escape_strlist;
 	escaped_copy;
+	fprocopen;
 	free_slabinfo;
 	freeproc;
 	get_ns_id;

proc/procio.3

@@ -0,0 +1,80 @@
+'\" t -*- coding: UTF-8 -*-
+.\"
+.\" This file describes the readproc interface to the /proc filesystem
+.\"
+.\" Copyright 2018 Werner Fink <werner@suse.de>
+.\"
+.\" Permission is granted to make and distribute verbatim copies of this
+.\" manual provided the copyright notice and this permission notice are
+.\" preserved on all copies.
+.\"
+.\" Permission is granted to copy and distribute modified versions of this
+.\" manual under the conditions for verbatim copying, provided that the
+.\" entire resulting derived work is distributed under the terms of a
+.\" permission notice identical to this one
+.\"
+.\" Formatted or processed versions of this manual, if unaccompanied by
+.\" the source, must acknowledge the copyright and authors of this work.
+.\"
+.TH PROCIO 3 "16 January 2018" "Linux Manpage" "Linux Programmer's Manual"
+.SH NAME
+fprocopen \- stream open functions on files below /proc/##
+.SH SYNOPSIS
+.B #define _GNU_SOURCE
+.br
+.B #include <stdio.h>
+.br
+.B #include <proc/procio.h>
+.sp
+.BI "FILE *fprocopen(const char *path, const char *mode);
+
+.SH DESCRIPTION
+
+The
+.B fprocopen
+function opens files below
+.I /proc/##
+whose name is the string to by path and associates a stream with it.
+The argument
+.I mode
+points to a string beginning with one of the following sequences
+.TP
+.B r
+Open a file below
+.I /proc/##
+for reading even large buffers.  The stream is positioned at
+the beginning of the file.
+.TP
+.BR w [ <del> ]
+Open a file below
+.I /proc/##
+for writing even large buffers.  The optional delimeter character
+can be one of the follwoing
+.BR '\ ' ,\  ',' ,\  '.' ,\ and\  ':'
+where the default is the colon
+.BR ',' .
+This allows to split very large input lines into pieces at this
+delimeter and write each of them to the opened file below
+.IR /proc/## .
+.TP
+.B e
+The underlying file descriptor will be closed if you use any
+of the ‘exec...’ functions within your code.
+.PP
+The internal API allows to use stdio functions to read and write
+large buffers below
+.IR /proc/## .
+.PP
+.SH SEE ALSO
+.BR fopen (3),
+.br
+.BR fopencookie (3)
+.br
+.BR setvbuf (3)
+.br
+.BR lseek (3)
+.PP
+.SH COPYRIGHT
+2018 Werner Fink,
+.SH AUTHOR
+Werner Fink <werner@suse.de>

proc/procio.c

@@ -0,0 +1,293 @@
+/*
+ * procio.c -- Replace stdio for read and write on files below
+ * proc to be able to read and write large buffers as well.
+ *
+ * Copyright (C) 2017 Werner Fink
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#ifndef _GNU_SOURCE
+# define _GNU_SOURCE
+#endif
+#include <errno.h>
+#include <fcntl.h>
+#include <libio.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+
+typedef struct pcookie {
+	char	*buf;
+	size_t	count;
+	size_t	length;
+	off_t	offset;
+	int	fd;
+	int	delim;
+	int	final:1;
+} pcookie_t;
+
+static ssize_t proc_read(void *, char *, size_t);
+static ssize_t proc_write(void *, const char *, size_t);
+static int proc_close(void *);
+
+__extension__
+static cookie_io_functions_t procio = {
+    .read  = proc_read,
+    .write = proc_write,
+    .seek  = NULL,
+    .close = proc_close,
+};
+
+FILE *fprocopen(const char *path, const char *mode)
+{
+	pcookie_t *cookie = NULL;
+	FILE *handle = NULL;
+	mode_t flags = 0;
+	size_t len = 0;
+	int c, delim;
+
+	if (!mode || !(len = strlen(mode))) {
+		errno = EINVAL;
+		goto out;
+	}
+
+	/* No append mode possible */
+	switch (mode[0]) {
+	case 'r':
+		flags |= O_RDONLY;
+		break;
+	case 'w':
+		flags |= O_WRONLY|O_TRUNC;
+		break;
+	default:
+		errno = EINVAL;
+		goto out;
+	}
+
+	delim = ',';				/* default delimeter is the colon */
+	for (c = 1; c < len; c++) {
+		switch (mode[c]) {
+		case '\0':
+			break;
+		case '+':
+			errno = EINVAL;
+			goto out;
+		case 'e':
+			flags |= O_CLOEXEC;
+			continue;
+		case 'b':
+		case 'm':
+		case 'x':
+			/* ignore this */
+			continue;
+		default:
+			if (mode[c] == ' ' || (mode[c] >= ',' && mode[c] <= '.') || mode[c] == ':')
+				delim = mode[c];
+			else {
+				errno = EINVAL;
+				goto out;
+			}
+			break;
+		}
+		break;
+	}
+
+	cookie = (pcookie_t *)malloc(sizeof(pcookie_t));
+	if (!cookie)
+		goto out;
+	cookie->count = BUFSIZ;
+	cookie->buf = (char *)malloc(cookie->count);
+	if (!cookie->buf) {
+		int errsv = errno;
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+	cookie->final = 0;
+	cookie->offset = 0;
+	cookie->length = 0;
+	cookie->delim = delim;
+
+	cookie->fd = openat(AT_FDCWD, path, flags);
+	if (cookie->fd < 0) {
+		int errsv = errno;
+		free(cookie->buf);
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+
+	handle = fopencookie(cookie, mode, procio);
+	if (!handle) {
+		int errsv = errno;
+		close(cookie->fd);
+		free(cookie->buf);
+		free(cookie);
+		errno = errsv;
+		goto out;
+	}
+out:
+	return handle;
+}
+
+static
+ssize_t proc_read(void *c, char *buf, size_t count)
+{
+	pcookie_t *cookie = c;
+	ssize_t len = -1;
+	void *ptr;
+
+	if (cookie->count < count) {
+		ptr = realloc(cookie->buf, count);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+		cookie->count = count;
+	}
+
+	while (!cookie->final) {
+		len = read(cookie->fd, cookie->buf, cookie->count);
+
+		if (len <= 0) {
+			if (len == 0) {
+				/* EOF */
+				cookie->final = 1;
+				cookie->buf[cookie->length] = '\0';
+				break;
+			}
+			goto out;		/* error or done */
+		}
+
+		cookie->length = len;
+
+		if (cookie->length < cookie->count)
+			continue;
+
+		/* Likly to small buffer here */
+
+		lseek(cookie->fd, 0, SEEK_SET);	/* reset for a retry */
+
+		ptr = realloc(cookie->buf, cookie->count += BUFSIZ);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+	}
+
+	len = count;
+	if (cookie->length - cookie->offset < len)
+		len = cookie->length - cookie->offset;
+
+	if (len < 0)
+		len = 0;
+
+	if (len) {
+		(void)memcpy(buf, cookie->buf+cookie->offset, len);
+		cookie->offset += len;
+	} else
+		len = EOF;
+out:
+	return len;
+}
+
+#define LINELEN	4096
+
+static
+ssize_t proc_write(void *c, const char *buf, size_t count)
+{
+	pcookie_t *cookie = c;
+	ssize_t len = -1;
+	void *ptr;
+
+	if (!count) {
+		len = 0;
+		goto out;
+	}
+
+						    /* NL is the final input */
+	cookie->final = memrchr(buf, '\n', count) ? 1 : 0;
+
+	while (cookie->count < cookie->offset + count) {
+		ptr = realloc(cookie->buf, cookie->count += count);
+		if (!ptr)
+			goto out;
+		cookie->buf = ptr;
+	}
+
+	len = count;
+	(void)memcpy(cookie->buf+cookie->offset, buf, count);
+	cookie->offset += count;
+
+	if (cookie->final) {
+		len = write(cookie->fd, cookie->buf, cookie->offset);
+		if (len < 0 && errno == EINVAL) {
+			size_t offset;
+			off_t amount;
+			char *token;
+			/*
+			 * Oops buffer might be to large, split buffer into
+			 * pieces at delimeter if provided
+			 */
+			if (!cookie->delim)
+				goto out;		/* Hey dude?! */
+			offset = 0;
+			do {
+				token = NULL;
+				if (cookie->offset > LINELEN)
+					token = (char*)memrchr(cookie->buf+offset, ',', LINELEN);
+				else
+					token = (char*)memrchr(cookie->buf+offset, '\n', LINELEN);
+				if (token)
+					*token = '\n';
+				else {
+					errno = EINVAL;
+					len = -1;
+					goto out;	/* Wrong/Missing delimeter? */
+				}
+				if (offset > 0)
+					lseek(cookie->fd, 1, SEEK_CUR);
+
+				amount = token-(cookie->buf+offset)+1;
+				ptr = cookie->buf+offset;
+
+				len = write(cookie->fd, ptr, amount);
+				if (len < 1  || len >= cookie->offset)
+					break;
+
+				offset += len;
+				cookie->offset -= len;
+
+			} while (cookie->offset > 0);
+		}
+		if (len > 0)
+			len = count;
+	}
+out:
+	return len;
+}
+
+static
+int proc_close(void *c)
+{
+	pcookie_t *cookie = c;
+	close(cookie->fd);
+	free(cookie->buf);
+	free(cookie);
+	return 0;
+}

proc/procio.h

@@ -0,0 +1,11 @@
+#ifndef PROCPS_PROC_PROCIO_H
+#define PROCPS_PROC_PROCIO_H
+
+#include "procps.h"
+
+EXTERN_C_BEGIN
+
+extern FILE *fprocopen(const char *, const char *);
+
+EXTERN_C_END
+#endif

sysctl.c

@@ -45,6 +45,7 @@
 #include "fileutils.h"
 #include "nls.h"
 #include "xalloc.h"
+#include "proc/procio.h"
 #include "proc/procps.h"
 #include "proc/version.h"
 
@@ -66,6 +67,10 @@ static bool IgnoreError;
 static bool Quiet;
 static char *pattern;
 
+#define LINELEN 4096
+static char *iobuf;
+static size_t iolen = LINELEN;
+
 /* Function prototypes. */
 static int pattern_match(const char *string, const char *pat);
 static int DisplayAll(const char *restrict const path);
@@ -158,14 +163,12 @@ static char *StripLeadingAndTrailingSpaces(char *oneline)
 /*
  * Read a sysctl setting
  */
-#define IOBUFSIZ    (128<<10)
-static char *iobuf;
 static int ReadSetting(const char *restrict const name)
 {
 	int rc = 0;
 	char *restrict tmpname;
 	char *restrict outname;
-	char inbuf[1025];
+	ssize_t rlen;
 	FILE *restrict fp;
 	struct stat ts;
 
@@ -220,7 +223,7 @@ static int ReadSetting(const char *restrict const name)
 		goto out;
 	}
 
-	fp = fopen(tmpname, "r");
+	fp = fprocopen(tmpname, "r");
 
 	if (!fp) {
 		switch (errno) {
@@ -243,11 +246,8 @@ static int ReadSetting(const char *restrict const name)
 			break;
 		}
 	} else {
-	    if (iobuf)
-            setvbuf(fp, iobuf, _IOFBF, IOBUFSIZ);
-
 		errno = 0;
-		if (fgets(inbuf, sizeof inbuf - 1, fp)) {
+		if ((rlen = getline(&iobuf, &iolen, fp)) > 0) {
 			/* this loop is required, see
 			 * /sbin/sysctl -a | egrep -6 dev.cdrom.info
 			 */
@@ -256,23 +256,23 @@ static int ReadSetting(const char *restrict const name)
 				if (PrintName) {
 					fprintf(stdout, "%s = ", outname);
 					do {
-						fprintf(stdout, "%s", inbuf);
+						fprintf(stdout, "%s", iobuf);
-						nlptr = &inbuf[strlen(inbuf) - 1];
+						nlptr = &iobuf[strlen(iobuf) - 1];
 						/* already has the \n in it */
 						if (*nlptr == '\n')
 							break;
-					} while (fgets(inbuf, sizeof inbuf - 1, fp));
+					} while ((rlen = getline(&iobuf, &iolen, fp)) > 0);
 					if (*nlptr != '\n')
 						putchar('\n');
 				} else {
 					if (!PrintNewline) {
-						nlptr = strchr(inbuf, '\n');
+						nlptr = strchr(iobuf, '\n');
 						if (nlptr)
 							*nlptr = '\0';
 					}
-					fprintf(stdout, "%s", inbuf);
+					fprintf(stdout, "%s", iobuf);
 				}
-			} while (fgets(inbuf, sizeof inbuf - 1, fp));
+			} while ((rlen = getline(&iobuf, &iolen, fp)) > 0);
 		} else {
 			switch (errno) {
 			case EACCES:
@@ -439,10 +439,7 @@ static int WriteSetting(const char *setting)
 		goto out;
 	}
 
-	fp = fopen(tmpname, "w");
+	fp = fprocopen(tmpname, "w");
-
-	if (iobuf)
-		setvbuf(fp, iobuf, _IOFBF, IOBUFSIZ);
 
 	if (!fp) {
 		switch (errno) {
@@ -503,20 +500,17 @@ static int pattern_match(const char *string, const char *pat)
 	return (1);
 }
 
-#define LINELEN 4096
-
 /*
  * Preload the sysctl's from the conf file.  We parse the file and then
  * reform it (strip out whitespace).
  */
 static int Preload(const char *restrict const filename)
 {
-	char oneline[LINELEN];
-	char buffer[LINELEN];
 	FILE *fp;
 	char *t;
 	int n = 0;
 	int rc = 0;
+	ssize_t rlen;
 	char *name, *value;
 	glob_t globbuf;
 	int globerr;
@@ -544,13 +538,19 @@ static int Preload(const char *restrict const filename)
 		    ? stdin : fopen(globbuf.gl_pathv[j], "r");
 		if (!fp) {
 			xwarn(_("cannot open \"%s\""), globbuf.gl_pathv[j]);
-			return -1;
+			rc = -1;
+			goto out;
 		}
 
-		while (fgets(oneline, sizeof oneline, fp)) {
+		while ((rlen =  getline(&iobuf, &iolen, fp)) > 0) {
-			n++;
+			size_t offset;
-			t = StripLeadingAndTrailingSpaces(oneline);
 
+			n++;
+
+			if (rlen < 2)
+				continue;
+
+			t = StripLeadingAndTrailingSpaces(iobuf);
 			if (strlen(t) < 2)
 				continue;
 
@@ -569,6 +569,10 @@ static int Preload(const char *restrict const filename)
 			if (pattern && !pattern_match(name, pattern))
 				continue;
 
+			offset = strlen(name);
+			memmove(&iobuf[0], name, offset);
+			iobuf[offset++] = '=';
+
 			value = strtok(NULL, "\n\r");
 			if (!value || !*value) {
 				xwarnx(_("%s(%d): invalid syntax, continuing..."),
@@ -580,12 +584,16 @@ static int Preload(const char *restrict const filename)
 				value++;
 
 			/* should NameOnly affect this? */
-			sprintf(buffer, "%s=%s", name, value);
+			memmove(&iobuf[offset], value, strlen(value));
-			rc |= WriteSetting(buffer);
+			offset += strlen(value);
+			iobuf[offset] = '\0';
+
+			rc |= WriteSetting(iobuf);
 		}
 
 		fclose(fp);
 	}
+out:
 	return rc;
 }
 
@@ -807,7 +815,7 @@ int main(int argc, char *argv[])
 	argc -= optind;
 	argv += optind;
 
-	iobuf = (char*)malloc(IOBUFSIZ);	/* Allow to fail */
+	iobuf = xmalloc(iolen);
 
 	if (DisplayAllOpt)
 		return DisplayAll(PROC_PATH);